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5R Rifling

Posted
on November 15, 2016

Some of the buzz in Rifledom this year involves what is called 5R rifling. As the name implies, it features five lands and five grooves (traditional rifling has had as few as two grooves and as many as 16, with the more common numbers being 4 and 6).

Barrett "Boots" Obermeyer developed 5R rifling. He is a former U.S. Army type, who has made a name for himself in the target shooting community over the years.

“5R is the form of rifling I developed for use in most target barrels and in many sporting barrels,” he explained. “These barrels have 5 grooves, and the lands have angular sides. I have observed that bullet jackets will deform such that they remain closer to the R-form lands than they will to the sharp-edged lands present in conventional-style rifling. This reduces powder fouling at the corner of the grooves. The angled form of the lands also helps to reduce jacket failures in quick-twist barrels.”

RIFLING PROFILES SHOW the difference between traditional rifling (top) and 5R rifling (bottom). Not that the edges of 5R are not square (don’t cut into bullet jacket as much) and that with 5R, the lands are opposite of grooves while with traditional rifling, lands are opposite lands and grooves are opposite grooves.

There are all kinds of other things being said about 5R in Gundom, some logical and others, well, perhaps a bit of a stretch.

Some suggest the rifling profile results in a bit more velocity. Others point to extended barrel life and reduced copper fouling.

I have been shooting rifles with 5R and one thing is certain: the barrels I have been shooting have been very, very accurate. Don’t know if that is because they are just good barrels, or whether the 5R has contributed something extra. One thing is certain: 5R hasn’t hurt.

With respect to reduced fouling, that also makes sense. Such a configuration leaves many fewer areas and angles where fouling can build up, etc.

It is easy to become lost in minutia when discussing rifling. The number and impacts of the variables literally can be mind-boggling.

Some have opined that the 5R craze is little more than sales hype. May be. But in my humble opinion, 5R is also a real deal. Makes me at least somewhat excited.

There have been scads of different rifling styles, each invented for particular reason or reasons. As centuries have passed, some have gone, simply because the reasons they were invented no longer apply.

Such development always has happened during times of significant technological and manufacturing advancement.

There is no question that the advances in the firearms industry in recent years are tied directly to what some refer to as the “tactical” state of mind within Gundom. As a result, there have been incredible advances in function, reliability – even overall shootability.

Never in the history of Gundom have there been guns that shoot as well, last as long and are as trouble-free as right now. And things just keep getting better all the time.

Truly, this is an exciting time to be in the shooting sports. And if 5R rifling is part of the equation that results in companies being able to offer more accurate rifles that don’t foul as much or as quickly, all the better.